Caffeine is just as addictive as cocaine, scientists are saying these days.

"Uh-oh," you're probably muttering. "Now the health police are after my last indulgence, my morning coffee !" You needn't worry - much. If you're healthy, you don't have to give up caffeine.

Caffeine, unlike cocaine, is fairly harmless. However, too much caffeine can make you jittery, anxious and headachy, give you a stomachache, or interfere with your sleep. Withdrawing from a caffeine addiction can be extremely painful, so it's smart to know how much caffeine you're getting every day.

How much is too much ? Almost every person in America takes in caffeine in one form or another every day. Most coffee lovers drink about three and a half cups a day. A five-ounce cup of automatic drip coffee contains about 103mg of caffeine. ( That's cup, not mug. Mugs hold 10 ounces, or up to a whopping 206 mg of caffeine ). Most experts recommend you get no more than 250 to 450 mg of caffeine per day, depending on your weight, age and general health.

Overdoing it. Too much caffeine can cause abnormal heart rhythms or raise blood pressure, especially in people who aren't used to the jolt. It can affect cholesterol levels slightly, but recent research has suggested that any rise in LDL ("bad") cholesterol that it causes is offset by an equal rise in HDL ("good") cholesterol.

Drinking more than two cups of coffee a day can cause calcium loss, increasing the chance of osteoporosis and hip fracture. Coffee lovers, especially women, should drink a glass of milk a day to offset coffee's effect on bones.

Caffeine can also hinder the absorption of certain kinds of iron, including iron from supplements. If you're anemic, don't take your iron with your morning coffee ! And if you are pregnant or soon plan to be, it's best to avoid caffeine. Heavy use can increase the risk of miscarriage or low birth weight. It may also make you less fertile.

Caffeine and other drugs. Caffeine can intensify the effects of some stimulants, common cold remedies and hormones. It can cause extremely high blood pressure when combined with certain antidepressants. Make sure your doctor or pharmacist knows how much caffeine you drink.

Cold turkey ... er, coffee. Someone who consumes a lot of caffeine can find quitting, or even cutting back, rough going. Flu-like symptoms, insomnia, jangling nerves and a nasty headache are frequent consequences. Withdrawal symptoms usually start within 18 to 24 hours, but can begin earlier. In fact, the
"lift" your morning cup of coffee gives you may be simple relief from early withdrawal symptoms. If you need to cut down, do it gradually.

Now for the good news. Caffeine's stimulating effect can be useful. It can improve mental and physical performance, make a dull task go faster and help with fatigue on long drives. In military combat, it can keep soldiers alert and save lives. It helps some pain relievers work more efficiently, and research has shown it to "rev" the metabolism slightly. Dieters always appreciate even a slight metabolism boost.

The trick to healthy coffee consumption is balance and constancy. Since it is possible to develop a tolerance for caffeine, it's best not to get too much. Be aware that caffeine "hides" in unexpected places, and you may be consuming much more than you know. Read labels, and check the caffeine chart.

The caffeine
calculator

Beverages

Milligrams caffeine

Coffee, automatic drip ( 5 oz. cup )

80 - 150

Coffee, perked ( 5 oz. cup )

64 - 124

Coffee, instant ( 5 oz. cup )

40 - 108

Coffee, decaf ( 5 oz. cup )

2 - 5

Cocoa, hot ( 5 oz. cup )

4 - 6

Tea, brewed, 3 min. ( 5 oz. cup )

36 - 40

Tea, brewed, iced ( 12 oz. glass )

36 - 40

Cola drinks ( 12 oz. can )

36 - 46

"Specialty" Coffees

Espresso, 1.5 oz. ( demitasse cup )

15 - 30

Cappuccino ( 3 oz. espresso, 3 oz. milk )

30 - 60

Food

Chocolate bar, average size

15 - 30

Baking chocolate, unsweetened, 1 oz.

25

Chocolate cake, slice

20 - 30

Drugs ( adult dose )

No-Doz

200

Aqua-Ban

200

Excedrin

130

Fiorinal

80

Anacin, Empirin, midol

64

Darvon Compound

60

Norgesic

60

Let's say you want to limit yourself to no more than 350 mg of caffeine per 12-hour day. Suppose you like to have a mug of coffee in the morning and a cup after lunch. You're already near 309 mg - almost your limit. You could have a chocolate cupcake and a cup of hot tea, at 35 mg, for your total of 344, but no more coffee.

Or ... you could make that lunch cup decaf and "bank" about 103 mg - enough for a double cappuccino later. However, if you took Excedrin for a headache that day, you're a little over your limit, so better make that after-dinner coffee decaf. ( But you could still have the chocolate cupcake
).

Moderation, as in most things, is the key. In an age of "don'ts," isn't it nice to know that you can have your coffee - and eat your cake, too ?